The invention is directed to a connector that is impermeable to liquids having a first connector part, comprising a connector pin, and having a second connector part, comprising bushings matching the connector pin of the first connector part, with the connector, in the plug-in position, being sealed from any liquids accessing the connector pins and bushings by at least one peripherally extending circumferential sealing ring between the connector parts, and the plug-in position is secured by a rotational, axially fixed threaded bushing, which is supported at one of the connector parts fixed in the axial direction but rotational, and with its internal thread matching the fastening thread of the other connector part.
A plug-in connector of this type is known from EP 0 883 214 B1.
In such connectors the loosening of the two connector parts from each other can lead to difficulties in an environment where there is a risk of explosion, because when loosening the plug-in connection sparks can develop which may not have any effect in such an environment, though.